gitlab: Add soft check against bashisms

Even .sh (Unix) scripts being "forbidden" by us on Meson to
allowing GIMP being 100% natively built on Windows, it is a
good pratice anyway .sh being portable even outside Meson.

.gitlab-ci.yml

@@ -601,8 +601,8 @@ meson-health:
     - <<: *CI_COMMIT
   stage: analysis
   script:
-    - apt-get update
+    - apt-get update -qq
-    - apt-get install -y git
+    - apt-get install -qq -y --no-install-recommends git shellcheck devscripts
     - sh .gitlab/run_meson_health_diff.sh
   allow_failure: true
 

.gitlab/run_meson_health_diff.sh

@@ -2,11 +2,13 @@
 
 . .gitlab/search-common-ancestor.sh
 
+
+# CHECK SCRIPTS RUNNED BY MESON (ALL OSes)
+printf "\e[0Ksection_start:`date +%s`:nonunix_test[collapsed=false]\r\e[0KChecking for non-Unix compatibility\n"
 diff=$(git diff -U0 --no-color "${newest_common_ancestor_sha}" -- '*.build' '*.py' | grep -E '^\+[^+]' | sed 's/^+//')
 
-
+## List of commonly used utilities on Unix world
-#List of commonly used utilities on Unix world
+## See the context: https://gitlab.gnome.org/GNOME/gimp/-/issues/11385
-#See the context: https://gitlab.gnome.org/GNOME/gimp/-/issues/11385
 coreutils_list="
    \.sh \
    'sh' \
@@ -125,20 +127,18 @@ coreutils_list="
    'whoami' \
    'yes'
 "
-
 for coreutil in $coreutils_list; do
   if echo "$diff" | grep -q "$coreutil"; then
     found_coreutils="$(echo "$found_coreutils $coreutil" | sed 's|\\||g')"
   fi
 done
-
 if [ "$found_coreutils" ]; then
+  printf "$diff\n"
   printf '\033[31m(ERROR)\033[0m: Seems that you are trying to add an Unix-specific dependency to be called by Meson.\n'
   printf "         Please, port to Python (which is crossplatform), your use of:${found_coreutils}.\n"
 fi
 
-
+## Limited list of commonly used utilities on Windows world
-#Limited list of commonly used utilities on Windows world
 ntutils_list="
    \.bat \
    \.cmd \
@@ -146,23 +146,51 @@ ntutils_list="
    'cmd' \
    'powershell'
 "
-
 for ntutil in $ntutils_list; do
   if echo "$diff" | grep -q "$ntutil"; then
     found_ntutils="$(echo "$found_ntutils $ntutil" | sed 's|\\||g')"
   fi
 done
-
 if [ "$found_ntutils" ]; then
+  printf "$diff\n"
   printf '\033[31m(ERROR)\033[0m: Seems that you are trying to add a NT-specific dependency to be called by Meson.\n'
   printf "         Please, port to Python (which is crossplatform), your use of:${found_ntutils}.\n"
 fi
 
+if [ -z "$found_coreutils" ] && [ -z "$found_ntutils" ]; then
+  printf '(INFO): Meson .build and .py files are alright regarding being crossplatform.\n'
+fi
+printf "\e[0Ksection_end:`date +%s`:nonunix_test\r\e[0K\n"
 
-if [ "$found_coreutils" ] || [ "$found_ntutils" ]; then
+
-  echo "$diff"
+# CHECK SCRIPTS NOT RUN BY MESON (UNIX ONLY)
+# Shell scripts have potential portability issues if:
+# 1) contain bash shebang or are called by bash;
+# 2) contain bashisms.
+printf "\e[0Ksection_start:`date +%s`:unix_test[collapsed=false]\r\e[0KChecking for Unix portability (optional)\n"
+diff=$(git diff -U0 --no-color "${newest_common_ancestor_sha}" | grep -E '^\+[^+]' | sed 's/^+//')
+
+## Check shebang and external call (1)
+echo "$diff" | grep -E '^#!\s*/usr/bin/env\s+bash|^#!\s*/(usr/bin|bin)/bash(\s|$)' && found_bashism='extrinsic_bashism'
+echo "$diff" | grep -E "bash\s+.*\.sh" && found_bashism='extrinsic_bashism'
+
+## Check content with shellcheck and checkbashisms (2)
+for sh_script in $(find "$CI_PROJECT_DIR" -type d -name .git -prune -o -type f \( ! -name '*.ps1' ! -name '*.c' -exec grep -lE '^#!\s*/usr/bin/env\s+(sh|bash)|^#!\s*/(usr/bin|bin)/(sh|bash)(\s|$)' {} \; -o -name '*.sh' ! -exec grep -q '^#!' {} \; -print \)); do
+  shellcheck --severity=warning --shell=sh -x "$sh_script" | grep -v 'set option posix is' | grep -vE '.*http.*SC[0-9]+.*POSIX' | grep --color=always -B 2 -E 'SC[0-9]+.*POSIX' && found_bashism='intrinsic_bashism'
+  checkbashisms -f $sh_script || found_bashism='intrinsic_bashism'
+done
+
+if [ "$found_bashism" ]; then
+  printf '\033[33m(WARNING)\033[0m: Seems that you added a Bash-specific code (aka "bashism").\n'
+  printf "           It is recommended to make it POSIX-compliant (which is portable).\n"
+else
+  printf '(INFO): Shell .sh files are alright regarding being portable.\n'
+fi
+printf "\e[0Ksection_end:`date +%s`:unix_test\r\e[0K\n"
+
+
+if [ "$found_coreutils" ] || [ "$found_ntutils" ] || [ "$found_bashism" ]; then
   exit 1
 fi
 
-printf 'Meson .build files are alright regarding crossplatform.\n'
 exit 0